The present invention relates to a thermal printer and, more particular, to a platen roller for a thermal printer.
It is an object of a conventional printing press type postage meter to print a postage indicia on a present envelope characterized by producing a postage indicia of consistent print contrast across the printed indicia. Additionally, it is an objective of a conventional printing press type postage meter to obtain this print quality in the specified printing area for envelopes varying paper grades (i.e., smoothness), porosity and envelope contour in the printing area.
Of particular note is the effect of the envelope contour in the printing area on print quality. It is a requirement, for example, by the United States Postal Service, that the postage indicia be printed in the upper right corner of the envelope. The contents of a particular envelope can cause this area to assume a variety of contour characteristic due in large part to the thickness of the contents and the particular shape of the contents.
Conventional thermal printers have required a relatively flat surface in the print area in order to insure adequate print quality. Hence, the difficulty in applying thermal printing techniques to postage metering mailing machines and like applications.